#include <sys/socket.h>
#include <stdio.h>
#include <arpa/inet.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <sys/wait.h>
#include <sys/select.h>
#define BUF_SIZE 1024
void error_handling(const char* message);
int main(int argc, char *argv[]){
    int sock;
    char message[BUF_SIZE];
    int str_len;
    struct sockaddr_in serv_addr;

    if(argc!=3){
        printf("Usage : %s <IP> <port>\n", argv[0]);
        exit(1);
    }
    // step1
    sock = socket(PF_INET, SOCK_STREAM, 0);

    if(sock == -1){
        error_handling("socket() error");
    }

    // step2
    
    memset(&serv_addr, 0, sizeof(serv_addr));
    serv_addr.sin_family = AF_INET;
    serv_addr.sin_port = htons(atoi(argv[2]));
    serv_addr.sin_addr.s_addr = inet_addr(argv[1]);

    // step3
    if(connect(sock, (struct sockaddr*)&serv_addr, sizeof(serv_addr)) == -1){
        error_handling("connect() error!");
    }else{
        puts("Connected........");
    }
    // puts("connect success!");
    while(1){
        fputs("Input message(Q to quit): ", stdout);
        fgets(message, BUF_SIZE, stdin);

        if(!strcmp(message, "q\n") || !strcmp(message, "Q\n")){
            break;
        }

        write(sock, message, strlen(message));
        str_len = read(sock, message, BUF_SIZE - 1);
        message[str_len] = 0;
        printf("Message from server: %s", message);
    }
    
    close(sock);
    return 0;
}
void error_handling(const char* message){
    fputs(message, stderr);
    fputc('\n', stderr);
    _exit(1);
}